Control system and device therefor for submarine mines



April 30, 1946.

c. M. VAN ATTAET AL;

CONTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES Filed Feb. '7, 1942 7 Sheets-Sheet 1 INVENTORS QM. VAN ATTA R.H- WHITEHEAD April 30, 1946 c. M. VAN ATTA ET AL CONTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES Filed Feb. 7, 1942 7 Sheets-Sheet 2 I I) I l I07 T I08 I09 lll' I64 I66 INVENTORS I65 law/'8 C.M.VAN ATTA R, H. WHITEHEAD April 30, 1946. c. M. VAN ATTA ET AL 2 9 CONTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES Filed Feb. 7, 1942 7 Sheets-Sheet 3 INVENTORS C. M. VAN ATTA R. H. WHITEHEAD April 30, 1946. c. M. VAN ATTA ET AL 2,399,523

CONTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES Filed Feb. '7, 1942 7 Sheets-Sheet 4 INVENTOR5 VAN ATTA WHITEHEAD I C. M; VAN ATTA ET AL.

CONTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES April 30, 1946.

Filed Feb. '7, 1942 T Sheets-Sheet 5 INVENTORS C. M.VAN ATTA R. H. WHITEHEAD April 30, 1946. c. M. VAN ATTA ET-AL- C(SNTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES Filed Feb. 7, 1942 7 Sheets-She et INVENTORS C. M. VAN ATTA 2 W m P 0 mm S Z 43 w mm m A\ 3 m 596. mmm m\ 2 3 6 4 IM B 5 .l 5 m R. H. WHITEHE AD April 30, 1946. c. M; VAN ATTA ET AL CONTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES Filed Feb. 7, 1942 7 Sheets-Sheet 7 INVENTORS C M. VAN ATTA R. H. WhITEHEAD RNEY Patentecl Apr. 30, 1946 CONTROL SYSTEM AND DEVICE THEREFOR FOR SUBMARINE MINES,

Ches M- V Atta, hin ton. D... C... and

Richard .1- h teh Haven; Qna

Application February 7, 1942, Serial 9- REQ- 3 4 Cla ms.-

This invention relates to control systems and devices for a submarine mine adapted to be fired automatically upon the approach of a vessel and in which the possibility of premature detonation of the mine by mine sweepin Operations is sub? stantially reduced. More specifically, the int vention provides a mine firing system and apparatus therefor whereby the mine is in an unarmed condition until a certain number of cledecting signals have been received in predeter minedtime spaced relation.

In devices or this character heretofore proposed for guarding a mine against detonation in response to an electromagnetic field set up by an impulse of strong current applied to an electrical conductor attached to a vessel moving within the vicinity of the mine and insulated from the sea water within which it is immersed except at the iurthermost end thereof, hereinafter referred to as a mine sweeping operation, the control mechanism usually comprises rather delicate electromagnetic operated switching devices for controlling the arming of the mine and for counting the number of signals necessary to place the mine in an armed condition.

In the system of the present invention the mine is caused to be armed by certain cam controlled contacts i ted by a spring driven gear mechanism of simple and rugged construction and adapted to be set or adjusted at Will to a position orres onding to a pr d t ned n m f s nals necessary to bring the mine into a armed condition. Furthermore, the mine is rendered inefiectiye to receive or utilize additional signals within a predetermined period of time after an initial s nal has been received.

' One of the objects of the present invention is the provision of -new and improved means for cau sing the mine to fire in response to a predetermined number of vessels passing the same.

Another of the objects is the provision of means settable at will for delaying the arming of a mine until a predetermmed number of detecting signals have been received in predetermined time spaced r a ion. V

Another of the objects is to provide new and improved means settable at will for varying th number of detecting signals necessary to arm and detonate the min Another of the objects i th provision of new and mPr-Qv dmeans i r n1 n e ne responsiile to additional signals received within a predetermined interval of time after an initial si nal has been rec ived- Another of the objects is the provision of new a im ro ed .min .firing c nt ol mechanism which ,is economical .130 manufacture, r liable in operation. and sesscs al he Qua es 11 ed ess and re abi i yv mse vica Further otherobiects advanta es and imp ovemerits will be apparent from the followin d scription taken in connection with the accompanying drawings of which:

Fig. 1 is a View in section partly broken away of a submarine mine in accordance with a B eferred form of the invention;

Fig. 2 is a plan view of the station selection and firing control mechanism of Fig. i;

Fig. 3 is a view in elevation of the device of Fig. 2;

Fig. 4 is a greatly enlarged view, partly broken away and with the cover thereof in section, of the station selection and firing control device;

Fig. 5 is a view of the device taken substan: tially along the line 5.75 of Fig. 4;

Fig. 6 is a view partiall in section taken alon the line 6.6 of Fig. 5;

Fig. 7 is a view of the device taken substan-. tially along the line l'l of Fig. 4;

Fig. 8 is "a view partly broken away taken along the line '88 of Fig. 4;

Fig. 9 is a view partly in section taken sub,- stantially along the line 9-9 of Fig. 7; and

Fig. 10 shows in diagrammatic form a complete system suitable for use with the present invention.

Refer-ring now to the drawings and more particularly to Fig. -1 thereof on which is shown a submarine mine adapted to be laid on the bed of a body of water, the mine being indicated gen.- erallyby the numeral ll provided with a casing i2 preferably somewhat cylindrical in shape to which is fitted an end cap- 13 secured thereto as by the bolts I4, a gasket 15 being provided preferably between the casing and the cap to insure a watertight connection therebetween. The mine is provided with apertures 15 and I! within which are disposed certain hydrostatic devices adapted to insert a detonating device Within an explosive charge and to set a starting clock mechanism in operation respectively. Within the aperture I6 is disposed a member 18 secured to the casing or the mine as by the bolts I9 passing through a retaining ring 2-! whereby a flexible diaphragm 22 is secured in sealed relation to the casing. Slidably supported by the member I8 is a plunger or shaft 23 having a shoulder 2.4 thereon against which the flexible diaphragm 22 i damped as by the-nut 25 and Washer 25, the plunger having a soluble washer 21 clamped thereto as b the --nut 28 and washer 29. The soluble washer is adapted to engage a shoulder 3i within the aperture 16 whereby the shaft 23 is prevented from movement'inward until the soluble washer has dissolved or softened sumciently to permit the shaft to be extended by the pressure of the water on the flexible diaphragm.

The diaphragm is normally urged outward by the pressure otthe retractile spring 32 disposed on the plunger -23. fiecrired to the shaft 23 many suitable manner is a detonating device 33 adapted to be inserted within a booster charge 34 disposed within a chamber 35which may be braced, if desired, to the casing 12 as by the member 36.

Within the aperture I1 is disposed a supporting member 31 secured thereto as by the bolts 38, and a flexible diaphragm 39 sealed thereto as by the clamping ring 4|. Within the supporting member 31 is a plunger 42 being preferably expanded at the end 43 thereof and maintained in engagement with the flexible diaphragm by the retractile spring 44, the plunger 42 bein adapted to set a clock mechanism 45 in operation as the plunger is actuated by the pressure of the water within which the mine is ubmerged and thereby close certain electrical contacts to energize certain mine firing circuits and devices, as will more clearly appear as the description pro firing mechanism indicated generally by the numeral 15 of the type adapted to close an electrical circuitupon the approach of a vessel such, for example, as the mine firing device described in the copending patent application of James B. Glennon and Chester M. Van Atta, Serial No.

395,230, filed May 26, 1941, for improvements in ceeds. A cover 46 is provided preferably to pro- 7 tect the clock from injury as the. casing I2 is filled with an explosive 41 within the chamber formed by the partition 48. There is also provided a recessed portion 49 within the casing l2 having a houlder 5| thereon to which is secured as by the bolts 52 a mounting plate 53, a suitable gasket 59 being provided between the mounting plate and the shoulder to prevent the seepage of water therebetween. The mounting plate 53 is provided with a member 54 securedthereto in any suitable manner as by welding, or brazing the parts together and adapted to support the mounting plate 55 secured thereto asby the bolts 56. v

Supported by the mounting plate 551s asta'tion control and timing mechanism indicated generally by the numeral 51 and secured thereto as by the nuts 58, the station selecting mechanism being adapted to be set at anydesired station as by the crank or key 59, Fig. 4, adapted to be inserted into an aperture within the mounting plate 53 when the plug 6! is removed therefrom. Th plug 6|, it will be understood, is secured to the plate 53 in any suitable manner as by thread ing the parts together, a suitable gasket 62 being provided therebetween to, insure a watertight connection between the plug and the mounting plate. The clock or timing mechanism 51 is pro vided with a cable 63 extending therefrom and having a plurality of electrical conductors therein whereby the clock device 51 is in electrical connection with a terminal box .64 secured to a partition or plate 65 as by the screws 66. l

A slow acting relay 81 is secured preferably to the mounting plate 55 and provided with means such as a. copper slug disposed about the core of the relay for delaying the closure of the relay contacts for a predetermined period of time after the operating circuit to the Winding of the relay has been closed.

There is also provided within the casing l2 a partition 68 thereby forming a chamber 69 within which is disposed a battery BA, a suitable pad or cushion 1| being arranged between the batand the terminalbox. There is also provided a' Firing mechanism for a submarine mine in which a pivoted magnetic needle or bar is caused to rotate about a horizontal axis in response to the vertical component of the magnetic field adjacent the mine and thereby move a pair of contacts into electrical engagement with each other. The mine firing device 15 is electrically connected to the terminal box 64 as by the electrical conductors within the cable'lt e'xtending'therebetween. 7

A tubular member orv duct 11 i provided between the chamber and the partition 48 within which is disposed the cable 18 comprising a. pair of cable conductors connected at one end thereof to the detonating device 33 and at the'other end to the terminal or junction box 64. The starting clock is provided with a cable 19 passing preferably within a tubular member 8| extending between the cover 46 andthe partition '48 for establishing an electrical connection between the clock cable 82 extending between the relay 81 and the terminal box 64 whereby the relay is electrically connected to. the terminal box, the arrangement of circuits being shown in detail on Fig. 10.

tery and the inner walls of the chamber 99 to ,On Figs. 2 and 3 are shown a plan and elevational view respectively of the station selection and firing control mechanism 51 employed with the mine of Fig. 1, the mechanism comprising, among other elements, a cover 83 secured to a base plate 84 as by the nuts 85. The cover is provided with a transparent disk 86 disposed within an apertureat the top of the cover and secured thereto as by the retaining ring 81 and screws 88. Disposed within the cover is a cam member 89, Figs. 4 and 5, having an indicating line or arrow 9| thereon adapted to be brought into substantial alinement with a plurality of scale divisions 92 having indicia associated therewith whereby the clock may be set to a desired station by the key or crank 59, Fig. 4, in accordance with the number of signals required to cause the mine to be fired by the explosive charge.

There is also arranged in the cover 83 an aperture 93 through which the key 59 is adapted to be inserted when it is desired to Wind the clock to a predetermined selected station, the aperture having a cover 94 pivoted as at 95 and adapted to close the aperture in the position illustrated on Fig. 2, a pin-96 projecting therefrom being provided for this purpose. An electric cable 91 having a plurality of electrical conductors 98 therein is arranged within a bushing 99 within the cover whereby an external electric connection to the clock maybe established.

On Figs. 4, 5 and 7 are shown in considerably enlarged form, several views of the station selection and firing control device of the present invention in elevation and in section taken along the lines 5-5 and 'I-1 of Fig- 4 respectively, the detailed views of the mechanism illustrating an arrangement of parts within a structure which has been found to give satisfactory results. The station selection and firing control device comprises preferably twe coiled springs 99 and llil preferably of non-magnetic material such, for example, as phosphor bronzeor beryllium 'copper having one end thereof" secured to the posts I02 and I03 at a suitable. complementary recessed portion therein and the other end of;v the springs is secured to the shafts 164 and ltlirespectiyely, the posts I62 and I63 being clamped between the plates84 and 66, Fig. 4, as by the nuts I01 and ma threaded on the studs I69 and I l. I r spectively. The device also comprises a winding shaft Illhaving a gear II3 thereon and adapted to receive the crank 59 in the manner shown in dashed outlineon Fig. l, the gear I I3 being meshed with the gear M4 on the shaft H5. The shaft H5 also carries a. gear II6 secured thereto adapted to mesh with the gear I.I1 mounted on the shaft H8, the gear II1 being in meshed engagement with the gears H9 and I2I disposed on the shafts I64'and I65 respectively whereby the springs 69 and I6I are geared together and mutually coact to operate the cam member 89 afiixed to the shaft H8 as by the screw I22, Fig. 5, threadedwithin the end of the shaft, a spline I23 being provided preferably between the shaft and the cam to insure positive assembly of the cam upon the shaft in predetermined angular relation thereto.

The shaft I64 has secured thereto a ratchet member I24 adapted to be engaged by the pawls I25 and I26 pivotally mounted upon the gear I21 as at I28 and I29 respectively and urged into engagement with the ratchet member as by the springs I3I and I32 secured thereto, the J other ends of the springs being in engagement with the stop members I33 and I34 respectively secured to the gear I21 and rotatable therewith. It will, of course, be understood that the gear I21 is suitably mounted for rotation with respect to the shaft I64, as is well known in the art of clock mechanisms, whereby the shaft I64 and gear I21 may be independently rotated with respect to each other as the springs 99 and I6! are wound or unwound, as the case may be.

The clock mechanism comprises an escapement wheel I35 mounted upon the shaft I36 operativeiy connected to the gear I21 as by the shafts I31 and I38 and the gears afiixed thereto. The escapement wheel I35 is adapted to cause'the balance wheel I39 to be oscillated by the escapement member I4I aflixed to the shaft I42 which also supports the balance wheel, the balance wheel I39 being normally restrained from movement by the pin I43 secured ther'eto'which normally engages the arm I44 afiixed to the plunger I45, Fig; 9. The plunger I45is slidably supported within a sleeve I46 secured preferably to the plates 84 and I56 and provided with a slotted portion I41 therein within which the arm I44 is adapted to move. The plunger I45 is provided with a stop pin I48 normally held in engagement with the plate 84 by the spring I49 disposed within the sleeve I46 whereby the arm I44 is yieldably maintained within the path of travel of the pin I43 of the wheel I 39 and the operation of the clock is thus prevented until the arm I44. is moved away from the pin I43. For this purpose there is provided a bar I5I secured to the upper end of the plunger I45 'as by the nuts I52 and having a slotted portion I53 in each end thereof adapted to engage a complementary recessed portion within the plungers I54. The plungers I54 are. adapted to be retracted by the electromagnets I55 secured to the plate I86 as by the cover I56 and securelyclamped thereto as by the nut I51 and washer I56 arranged on the stud III extending through a suitable aperture within the cover. The plate I66 lspreferably recessed as at 16 I,-Fig. 9, thereby to 3 maintainthe eleotromasnets 1.55 in alinement with the bar 1H. and; the apertu es I 2 wit in the plat I46 I The lower end ofhe p ung r I45 is formed at anangle the manner illustrated at I63, Fig. 9, thereby providing acam follower adapted to be urged upward and maintained in the operated position by the cam I64 secured to the shaft II8 as by the Screw I65 and washer I66, a suitable spline or key between the cam member and the shaft being provided preferably to insure the maintenance of a predetermined angular rel tion between the cam member I64 and the cam 39 respectively disposed on opposite ends of the shaft H8. The cam member I64 may be made of any material suitable for the purpose such, for example, as aluminum and provided with a hub I61 seeured thereto in any suitable manner having a slotted disk I68 pivotally mounted thereon for rotative movement relative to the cam I64 and retained 'thereagainst by the collar I69 affixed to the hub as by riveting or staking the parts together.

The cam I64 is provided with a recessed portion I1I therein, Fig. 8, i ntermediate the cam and the slotted plate I68 within which is arranged a retractile spring I12 having, one end thereof in engagement with a pin I13 secured to the slotted disk and the other end connected to a pin I14 secured to the cam whereby th l d disk I68 is yieldably urged at one end of an arcuately shaped aperture I15 formed therein against a stop pin I16 secured to the cam member I64, the stop pin and arcuate aperture coacting to form an arrangement in which the movement of thefslotted disk relative to the cam membar is limited to a predetermined angular distance. The slotted disk or baffle plate I68 is provided with a pluralityof slots through which the plunger I45 is adapted'to move, the leading edge of each vslotted portion of the disk I68 being preferably tapered as at I11 to facilitate the passage of the plunger I45 at the tapered end I63 thereof above the disk I68 as the clock is operated by the spring motors thereof in response to the energization of the electromasn ts I55.

In operation the circuit to the electromagnet I55 is required to be closed only for a period of time suflicient to release the escapement and .allow the clock to operate until the cam I64 has movedsufiiciently to maintain the plunger I45 in a'r'aised position by an amount necessary to move the arm I44 clear of the path of travel of the pin I43 on the wheel I39, the clock mechanism continuing to operate until the edge [l8 of the disk member I68 of the next succeeding slotted portion of the disk moves beyond the path of travel of the end I19 of the plunger I45 thereby permitting the plunger to be forced by the spring I49 into the corresponding recessed portion of the cam I64 and bring the clock to rest.

As the station Selecting clock is wound by the key 59, the cam I64, of course, moves in the opposite direction and the portion I8I of the cam member I64 causes the plunger I45 to be moved upward therebyto permit movement of the cam member I64 in the direction to'wind the clock.

-As the cam I64 moves in a direction to urge the plunger I45 upward at the cam portion I8I thereof, the slotted disk I68 is restrained from movement by the plunger I45 and the disk I 68, therefore, is moved relative to the cam member I64 until the pin I 16 is brought into engagement with the end I82 of the arcuate portion I15 of the slotted cam, Fig. 3.- When this occurs, the plunger I45 is raised sufficiently by the cam portion IN or the cam I64 tocause the plunger to be forced above the edge I18 of the slotted'disk I68 by reason of the somewhatrounded condition or the edge I18 and the end I19 of the plunger whereby the slotted disk-I18 is'allowed to be moved by the retractile spring I12 to the position shown on Figs. 8 and 9 of the drawings, this cycle of operations being repeated for each additional station to which the clock is set. An arrangement is thus provided inwhich the plunger I45 is moved quickly to the unoperated position in response to the operation of the retractile spring I49 as the end I19 of the plunger is moved beyond the edge I18 of the disk or baiile plate I68 during the operation of the clock mechanism'thereby arresting the clock mechanism and causing the cam 89 thereof to be brought to rest in certain predetermined angular positionsthereof corresponding to different'station settings at the ex piration of predetermined intervals of time. I

The cam 89 will now be described'with particularity in accordance with a preferred construction thereof which has been found to produce satisfactory results. The cam 89 is provided with a plurality of lobes I83 thereon and a somewhat wider lobe I84 adapted to engage a follower secured to the contact spring I85 and move it into engagement with the'contact spring I86 whereby the contacts I85 and I86 are in closed position during the time that the cam 89 is at rest and disengaged from each other as the cam 89 moves from a position of rest. The contact springs I85 and I86 are suitably insulated from each other when the contacts are in open position as by suitable bushings I81 of hard rubber, Bakelite or the like and clamped to a support I88 as by the nuts I89, the support being sec-ured'to a plate I9I preferably of insulating material as by the tubular rivets I92 through which pass the insulated conductors I93 whereby an external electrical connection to the contact springs I85 and I86 is established.

There is also secured to'the cam member 89 a lobe I94 preferably'in alinement with one of the lobes I83 but disposed in a different plane whereby the contact springs I95 and I96 are adapted to be moved into engagement with each other by the lobe I94 when the clock has been operated to the firing positionthereof.

The cam member 89 is composed'preferably of insulating material suitable for the purpose such, for example,'as Bakelite, hard rubber or the like and provided with a hub I91 having a stop member I98 thereon adapted to engage the pin I99 disposed within a recessed portion 20I within the cam. member and thereby arrest the cam in the home or initial position thereof and prevent movement of. the cam beyond a predetermined angular position from the home position corresponding, in the illustrated embodiment of the invention, to station 8. The cam member 89 is secured to the hub in any suitable manner as by the tubular rivets 202. The stop pin I99 is secured to the plate'l06 and provided preferably with a shoulder 203 thereon against which the insulating plate I9I is adapted torrest, thereby additionally supporting the insulating plate I9I near the central portion thereof. There is also secured to the insulating plate I9I a pair of terminal connections 204 and 205 to which the electromagnet I55is connectedas by the conductors 200 and 206 from whence the circuit is continued by waylof the conductor 201 and the conductors indicated generally at 208 there. by providing an arrangement in which the external electrical connectionsto the electromag-. net I55 arefacilitated.

The operation of the system will best be under-s stood from consideration of Fig. 10 on which is shown in diagrammatic form the starting clock 45, the station selection and firing control clock 51 and the detecting and firing mechanism 15 of Fig. 1 electrically connected together and connected to a firing relay 61. The operationrof the firing relay during the time that the station selecting mechanism 5121s in an initial or home position, causes. the operation of the detonator D whereby the mine is exploded in response to the passage or approach of a'ship within the Vie cinity of the mine after a predetermined number of detecting signals have been received. I

The starting clock 45 may be of any type suit,- able for the purpose such, for example, as the clock disclosed in the copending application. of James B. Glennon and Chester M. Van Atta for improvements in Firing mechanism for a submarine mine, Serial No. 395,230, filed May 26, 1941, in which a plunger P is adapted to be actuatedby ahydrostat in response to the pressure of the water within which the mine i launched. The clock mechanism is actuated by a coiled spring 209 preferably of phosphor bronze 0r beryllium copper as the plunger'P is operated by the hydrostat against the pressur of the spring 2| I.

The firing mechanism 15 comprises a magnet ized needle or bar 2I2 pivoted as at 2I3 for rotation about a horizontal axi and maintained substantially in the position shown in dashed outline on Fig. 10 by a retractile spring 2I4 secured thereto. Whenever a large magnetic object such as a steel vessel approaches within the vicinity of the mine, the vertical component of the terrestrial field is altered sufliciently to swing the magnetized element 2I2i about the axis; 2l3- and close a pair of firing contacts PC, the firing contacts remaining in closed position by reason of the energization of the hold-on coil HO arranged adjacent the magnetized element. Whereas in the arrangement of Fig. 10 only sufficient of the firing mechanism is shown as will enable one skilled in the art to understand the present invention, it will be understood that, if desired, the station selection and control device 51 may b employed with mine firing mechanisms adapted to close a circuit in response to signals received by an induction coil or a plurality of induction coils connected together opposedly and matched with respect to each other whereby an electromotive force is generated by the coils in accordance with the gradient of the magnetic signals received. Furthermore, the magnetized bar 2I2 of Fig. 10 may, if desired, be automatically set to a predetermined position regardless of the latitude in which the device is disposed by any means suitable for the purpose such, for example, as the latitude setting means disclosed in the copending application of James B. Glennon and Chester M. Van Atta referred to hereinbefore. f

Let it be assumed, by way of example, that the submarine mine of Fig. 1 has been launched within a body of water of depth suflicient to cau e the operation of the flexible diaphragm 39 thereby setting the clock 45 .in operation and that the mine has been launched for a lengthof time sufficient to cause the soluble washer 21 to be dissolved or softened sufilciently to cause the deto- 18601133 to be inserted within the booster cha g 34 by the pressure of the water against the flexible diaphragm 22, Let it also be assumed that the clock mechanism 51 has been set to station 5, Fig. 10. The movement of the plunger P causes the escapement mechanism of the clock 45 to be released and the cam 2I5 thereof to be moved about the axis 2I6 until the cam is arrested by the end 2I'I of the slotted portion 2I8 thereof moving'into engagement with the stop pin 2I9. The movement of cam 2I5 causes cam contacts A and B to be closed at a predetermined time such, for example, as twenty minutes after the clock hydrostat has'operated, and the cam contacts C to be closed at the expiration of a subsequent interval of time, such as thirty-five minutes after the cam contacts A and B are closed. The cam contacts A, B and C are prevented vfrom reopening by the cam being brought to rest as the pin 2I9 is engaged by the end 2| I of the slot 2L8. As contacts A and B are moved to closed position, ground at contact B is applied by way of conductor ZZI to one terminal of the battery BA from whence the circuit is continued by way of conductor 222, closed contacts of cam A and conductor 223 to one end of a fuse F within a suitable latitude setting mechanism 224 such, for example, as the latitude setting mechanism of the copending application of James B. Glenno'n and Chester M. Van Atta hereinbefore referred to, from whence the circuit is continued to ground thereby operating the fuse F and setting the latitude setting mechanism into operation to adjust the spring 2M whereby the magnetized element 2I2 i given a predetermined setting with the firing contacts FC disengaged from each other. As the clock 45 continues to operate, contact C thereof is closed thereby connecting ground to conductor 225 extending to the Winding of relay 6! and to the armature 226 thereof. The arming cycle of the mine has now progressed sufiiciently for the electromagnet I55 of the station selecting clock 51 to be operated in response to the closure of the firing contacts by the approach of a steel vessel or by an electromagnetic impulse received from a sweep wire, as the case may be.

Assume, by way of example, that mine sweeping operations are proceeding in the vicinity of the mine and that the firing contacts F are moved into engagement with each other in response to an electromagnetic impulse received from a sweep wire. When this occurs a circuit is closed from positive terminal of battery BA, conductor 22 cam contacts A, conductor 223, winding of the hold-on coil HO, firing contacts FC, conductor 22?, cam contact E of the clock mechanism 5'1, conductor 22'8, winding of relay 61, conductor 225, cam contacts C of the clock 45, conductor 22! and thence to the negative terminal of battery BA thereby causing relay 6! to operate and the winding of the hold-on coil HO to be energized and set up an electromagnetic held within the vicinity of the magnetized bar 2I2 in a direction to maintain the firing contacts FC closed untfl the circuit thereto is interrupted at the cam E contacts. Reiay 61, it will be noted, is a slow operating relay by reason of a copper slug disposed on the magnet coil and the armature i226 thereof moves into engagement with its make contact after a predetermined period of time has elapsed since the operating circuit to the relay was closed. When this occurs, a circuit s closed from the negative terminal or battery BA, conductor 221, contacts of cam C, conductor 225, armature 226 and make contact of relay 5'1,

conductor 229, winding of electromagnet I55, c0nductor 223, cam contacts A, conductor 222 and thence to the positive terminal of battery BA thereby operating the electromagnet I55 and setting the cycling clock mechanism into operation. The operation of the electromagnet I55, it will be recalled, withdraws the plunger I45, Fig. 9, away from the cam member I64 by an amount suincient to remove the arm I44 from the path of travel of the pin I43 whereby the balance wheel I39 is. released for operation by the escapement mechamsm.

The cam 89 is rotated in a counterclockwise direction by the escapement mechanism to the next succeeding lower numbered station setting and as the cam moves a sufficient distance to cause the E contacts thereof to be opened, the operating circuit to the relay 6'! is interrupted and the relay releases. As armature 226 of relay 6! moves away from the make contact thereof the operating circuit to the electromagnet I55 is interrupted and the electromagnet is deenergized. The plunger I45, however, does not release surficiently at this time to move the arm I44 thereof into the path of travel of the pin I43 by reason of the cam I54 having been moved through a suificient distance to hold the plunger operated until the clock mechanism has advanced to the next succeeding lower numbered station. An arrangement is thus provided in which the electromagnet I is energized for a relatively short period of time and the drain on the battery is reduced to a minimum. Whereas, in the illustrated embodiment of the invention shown on the drawings, a slow acting relay is employed to effect a delay in the closure of the firing circuit to the detonator D in response to the operation of the firing contacts FC when the station selection clock is in the home or initial position, it will be understood that this is by way of illustration only, as electro-responsive delay devices with a delay mechanism comprising clockwork, escapement wheels, dash pots or other delay means suit able for the purpose may be employed.

As the cam I64 of the clock 51 moves into a station position, the edge I18, Fig. 9 of the slotted disk I68 moves out of the path of travel of the end I19 of the plunger I45 thereby permitting the plunger to be moved by the retractile spring I49 to the position shown on Fig. 9 and bring the clock to rest. As cam contacts E are moved to open position, the energizing circuit for the holdon coil H0 is interrupted thereby causing the hold-on coil to be deenergized and permitting the firing contacts FC to be disengaged as the magnetized bar 2I2 is restored to the initial position thereof by the retractile spring 2I4 in response to the discontinuance of the electromagnetic impulse received.

As cam 89 moves into the station 4 position the contacts E thereof are closed thereby preparing a circuit to the firing control mechanism I5 whereby the electromagnet I 55 is again brought under the control of the firing contacts FC. The time required for the cam 89 to be moved by the spring mechanism from a particular station setting to a setting corresponding to the next succeeding lower numbered station is determined by the ratio of gears employed in the gear train and the rate of the oscillations of the balance wheel I39 thereof, a time interval of substantially three minutes, for example, having been found to produ'ce satisfactory results,

Let it be assumed that the firing contacts FC are moved to closed position by another impulse from a sweep wire thereby closing a circuit from the positive terminal of battery BA, conductor 222, cam contacts A, conductor 223, hold-on coil HO, firing contacts FC, conductor 221, cam E contacts, conductor 228, winding of relay 81, conductor 225, cam contacts, conductor HI and thence with the negative terminal of battery BA thereby operating relay 61 and energizing the hold-on coil in a direction to maintain the firin contacts closed. The energization of the coil winding of relay 61 causes the armature 226 thereof to be moved, after a suitable time delay, into engagement with the make contact thereof thereby operating. the electromagnet I55 and setting the clock 51 in operation. As the cam 89 moves away from the station 4 position, contacts E thereof are disengaged thereby interrupting the circuit to the hold-on coil and the relay 61. The hold-on coil is deenergized thereby permitting the firing contacts to be moved to open position by the latitude setting spring 2I4 and the release of the relay 61 at the armature 22B thereof causes the electromagnet I55 of the station selection clock 51 to be deenergized, but the plungers I54 thereof and the member I45 are preventedfrom releasing at this time sufiiciently to arrest the escapement mechanism of the clock by reason of the cam I54 which, it will be recalled, has moved sufliciently to maintain the plunger I45 in the operated position when the cam 89 has moved sufficiently to disengage contacts E.

As the clock moves into the station 3 position the edge I18 of the baflle plate I68 moves beyond the path of travel of the end I19 of the plunger I45 and the plunger, therefore, is forced into the released position by the retractile spring I49 such that the stop pin I48 thereof engages the plate 84 andrthe arm I44 secured thereto is engaged by the pin I43 of the balance wheel I39. The clock is thus brought to rest in the position corresponding to station 3. As the cam 89 moves into the station 3 position the cam contacts E are moved to closed position and the clock is again brought under the control of the firing contacts In the event that a steel vessel approaches within the vicinity of the mine, the firing contacts FC are moved to closed position thereby causing the relay 61 to operate and the hold-on coil to be energized. The operation of relay 61 caused the start magnet I55 of the clock 51 to operate thereby setting the clock in operation. As the cam 89 moves out of the station 3 position, cam contacts E are disengaged thereby causing the hold-on coil to be deenergized and the relay 51 to release. The release of relay 61 interrupts the operating circuit to the start magnet I55, the clock mechanism, however, continuingtooperate by reason of the movement of cam I64 from the station 3 position thereof. When the'vessel has moved a suflicient distance beyond the mine the magnetized bar 2I2 is moved by the spring 2M sufficiently to cause the firing contacts FC to open. As the clock moves into the station 2 position the contacts E thereof are closed. The clock is brought to rest in the station 2 position as the end I19 of the plunger I45 passes over the edge I18 of the baffle plate I88. I

As the firing contacts are moved to the closed position by a change in the magnetic field adjacent thereto caused by either a vessel or by a sweep wire, as the case may be, the operation of relay 61 causes the start magnet I55 to operate thereby releasingthe escapement mechanism and causing the cam 89 to be advanced to the station I position, relay 61 and the start magnet I55 releasing in response to the disengagement of cam E contacts as the cam 89 moves away from the station 2 position. As the clock moves into the station I position the contacts E- are again closed but the relay 61 and start magnet I55 do not operate at this time for the reason that the firing contacts FC have moved to open position during the movement of the cam 89 from the station 2 position to the station I position.

As the cam 89 moves into the initial or station I position the lobe I94 thereof causes the contacts F to close thereby arming the mine. i

As a vessel approaches within the vicinity of the armed mine the disturbance in the magnetic field adjacent thereto causes the magnetized element 2I2 to be moved to firing position thereby closing the firing contacts FC. When this occurs a circuit is closed from the positive terminal of battery BA, conductor 222, cam contacts A, conductor 223, winding of hold-on coil H0, firing contacts FC, conductor 221, cam contact E of the station selection clock 51, conductor 228, winding of relay 61, conductor 225, .cam contact C, conductor 22I and thence to the negative terminal of battery BA thereby energizing the hold-on coil in a direction to maintain the firing contacts closed, and causing the relay 61 to operate.

Relay 81, it will be recalled, is a slow-to-operate relay and the armature 228 thereof does not move into engagement with its make contact until a predetermined period of time has elapsed sufiicient to permit the vessel to attain a position directly above the mine before the mine is exploded whereby the explosion of the mine will occur beneath a vulnerable portion of the vessel and the maximum destructive effect thereof is obtained. As armature 226 of relay 61 moves into engagement with its make contact the start magnet I 55 of the station clock 51 is energized but the cam 89 is prevented from movement beyond the station I or home position by reason of the engagement of the portion 23I of the member I98 disposed within the recessed portion 20I thereof by the stop pin I99. As armature 225 of relay 61 moves into engagement with the make contact thereof a circuit is also closed from the negative terminal of battery BA, conductor 22I, cam contact 0, conductor 225, armature 225 and make contact of relay 81, conductor 229, cam contacts F of the clock 51, conductor 232, detonator D, conductor 223, cam contact A, conductor 222, and thence to the positive terminal of battery BA thereby causing the detonator D to operate and explode the mine.

Whereas in the foregoing example the clock is assumed to be set to station 5, it will be understood that the clock may be set to any desired station and the number of signals received by the clock necessary to arm the mine will, of course. be controlled by the station at which the clock is initially set. An arrangement is thus provided in which the mines comprising a, mine field may, in accordance with the present invention, be arranged in such a. manner that certain of the mines will be armed in response to one signal received from an outside source such, for example, as a sweep wire, others of the mines will be armed by two signals and still others of the mines by different numbers of signals, and the enemy, therefore, will be unable to sweep all of the mines of a particular mine field by a single mine sweepcontrol mechanism in which a predetermined number of changes in a magnetic field are required at predetermined successive intervals or time to arm the mine and in which the closure of the mine firing circuit in response to the approach of a vessel is delayed sufiiciently to cause the mine to explode underneath a vulnerable portion of the vessel. Furthermore, it will be understood that any suitable device for detecting the approach of a vessel may be employed in which an outgoing circuit is closed'by any suitable means suchg for example, asthe closure of a pair of electrical contacts or the operation of a thermi-f onic or other-suitable amplifying device arranged; between the detecting mechanism and the station:

selection and firing control mechanism 57.

While the invention has been described with particularity as to one preferred embodiment of a combination of mechanisms and of each of the various elements of the combination, it is to be understood that has been done for the purpose of disclosure and that various changes and substitutions may be readily apparent to those skilled in the art, after understanding'the invention herein disclosed, and the terms emplo ed in the appended claims are, therefore, to be consid ered as words of description rather than of limitation.

The invention herein described and claimed may be manufactured and used by error the Government of the United States of America for governmental purposes without the payment 0 any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the (Tnited 'States is:

.1. In a submarine mine of the character disclosed disposed within a body of water adjacent the path of travel of a vessel, a source of power, an electric circuit, means responsive to a disturbance in the terrestrial magnetic field adjacent the mine for closing the electric circuit, a detonating device, a station selecting device having a home position and a plurality of movedipositions corresponding to different station settings respectively, means for setting said station selection device to any of said station settings, means including a spring motor for actuating said station selecting device, means for releasably arresting the station selecting device in any or said oved positions thereof, means including an electroresponsive device controlled by said circuit closing .means for causing said station selection device to be advanced to the next succeeding station, inea'ns eiiective when the station selecting mechanism is in said home position for closing a, circuit in part to said detonating device, and means controlled by said last named circuit closing means for causing the detonating device to be operated by said source of power in response to the closure of said first named circuit closing means.

2. In a submarine mine of the character disclosed disposed within a body of water adjacent the'pat-h of travel of a vessel, a source or power, an electric circuit, means responsive to a disturbsince in the terrestrial magnetic field adjacent the mine for closing the electric circuit. a detnatmg device, a clock mechanism having a home position and a plurality of moved positions correspondin to different station settingsr'espectively, a first pair of contacts adapted to be closed as the clock is moved into any of said moved positions, means for setting said clock mechanism to any of said moved positions, means including a spring motor for actuating said clock mechanism, means for releasably arresting the clock mechanism in any or the moved positions thereof, meansihcluding an electro responsive device controlled by said first pair of conta'ctsan'd said circuit closing means for causing the clock mechanism to be advanced to the next succeeding position, a second pair of contacts adapted to be closed when the clock mechanism is actuated to said home position, and a firing circuit controlled by said second pair or contacts for causing the dctcnating device to be operated by said source of power in response to the closure of said electrlc circuit by said circuit closing means.

3. In a system of the character disclosed adapted to control the firing of a submarine mine arranged within a body of water, a circuit, a source of electrical power, means responsive to a change in the magnetic field adjacent the mine for energizing the circuit from said source of electrical power, a clock mechanism adapted to be o erated in unit cycles, electro responsiv means controlled by said circuit for causing said clock mechanism to be set inoperation to perform a unit cycle of operations, detonating means ada ted to be "operated by said source of electrical power, and means for causing the detonatin-g means to be operated in response tothe energization of said circuit when said clock mechanism has made a predetermined number of unit cycles of operation.

'4. In a system of the character disclosed for controlling the firing of a submarine mine, a circuit, means responsive to a change in the ma neuc field adjacent the mine for closing the circuit, a clock mechanism adapted to operate in unit cycles, elective-res onsive means controlled by said circuit adapted to set the clock mechanism in operation successively to perform one of said unit cycles of operation, each time said circuit is closed, means for setting said clock mech- 'anism to an initial setting correspond to a predetermined number of unit cycles of operations to be performed, a source of electrical power, detonating means and means effective when the clock mechanism has performed said predetermined number "of unit cycles of operation for causing said deton'ating means to be operated by said source of power in response to the closure of said circuit by said circuit closing means.

5. 'In "a system of the character disclosed for selectively "controlling the firing of a submarine mine arranged within a body of water, a circuit, a source of electrical power, means responsive to a change in the'm'agnetic field adjacent the mine for closing saidcircuit from said source of electrical power, a clock device operable in unit cycles and'havin'g 'a pair oi normally closed contacts in said circuit adapted to be disengaged during each of the cycles of operation thereof, a slow acting relay device in said circuit and adapted to be operated when the circuit is closed by said circuit closing means and the normally closed contacts are closed, means for releasing said clock device successively to perform said unit cycles of oper tion, means for arresting the clock device as each of said cycles of operation is completed, a pair of normally open contacts adapted to be closed when the clock device has made a predetermined number of unit cycles of operation, and a detonating device operatively connected to said normally open contacts and adapted to fire the mine in response to the operation of said slow acting relay device while the normally open contacts are closed.

6. In a device for controlling the firing of a submarine mine in accordance with a predetermined number of signal conditions received corresponding respectively to changes in the magnetic fieldadjacent thereto, the combination of means including a circuit closing device for detecting said changes in the magnetic field, a rotatable member having a firing position and a plurality of moved positions corresponding respectively to different numbers of signals required to arm the mine, means for initially setting said rotatable member to any of said moved positions,

means controlled by said circuit closing device for.

actuating said rotatable member from each moved position to an adjacent position in successive order as changes in said magnetic field are detected by said detecting means, detonating means, and means effective when the device has been armed for causing the detonating means to fire the mine in response to the operation of said circuit closing device as a change in said magnetic field is detected by said detecting means.

7. In a device for controlling thefiring of a submarine mine, the combination of a source of electrical power, detecting means comprising a circuit closing device adapted to be moved to circuit closing position in response to a change in the magnetic field adjacent thereto, means controlled by the pressure of the water'within which the mine is submerged for connecting said circuit closing device to said source of electrical power,

a spring operated clock mechanism having a rotatable element settable to a firing position and to a plurality of different positions corresponding respectively to the number of changes in said magnetic field required to arm the mine, means for settin said rotatable element to a predetermined one of said different positions, means including a stop member for releasably arresting the clock mechanism in each of said positions, a pair of contacts in electrical connection with said circuit closing device adapted to be closed as said rotatable element moves into each of said different positions, a relay device adapted to be operated selectively by said circuit closing'device in accordance with the operated condition of said pair of contacts, electro-responsive means controlled by said relay device adapted to operate said stop member and thereby release the rotatable element for operation to the next succeeding position thereof, means including a cam i or main taining said stop member operated until the rotatable element thereof has been advanced to said next succeeding position, an explosive charge arranged within the mine, a firing circuit having a detonating device therein adapted to fire said explosive charge, and means effective when the rotatable element has moved into said firing positlon for rendering said firing circuitv effective to be operatively connected to said source of power by said relay device and thereby explode the mine in response to theclosure of said circuit closing device.

8. In a system for controlling the firing of a submarine mine selectively in accordance with the number of signals received corresponding respectively to a predetermined number of changes in the earths magnetic field adjacent thereto, a source of power, means responsive to said changes in the magnetic field adapted to close a circuit from said source of power, a clock device having a rotatable shaft settable to an initial position and to a plurality of moved station positions, a spring motor adapted to operate said shaft from any of said moved positions to said initial position, a pair of normally closed contacts, means including a cam secured to said shaft and rotatable therewith for causing said contacts to be engaged when said cam is set to any of said positions and adapted to cause said contacts to be disengaged as the cam moves away from each station position, means for releasably arresting said shaft in each station position and in the initial position thereof, an electroresponsive device controlled by said contacts adapted to be operated by said circuit closing means and thereby release said shaft for rotation to the next succeeding station position, a second cam device secured to said shaft and rotatable therewith adapted to prevent the release ofsaid electro-responsive device as said contacts are moved to open position until the shaft moves into the next'succeeding station position, a second pair of contacts adapted to be closed by said rotatable cam as the shaft moves into said initial position, an explosive charge, detonating means and means for causing said explosive charge to be fired by the detonating means in response to a change in the magnetic field when said second pair of contacts have been closed.

9. In a system for controlling the firing of a submarine mine selectively in accordance with the number of signals received corresponding respectively to a predetermined number of changes in the earths magnetic field adjacent thereto, a source of power, means including a pair of firing contacts responsive to said changes in the ma netic field adapted to close a circuit from said .source of power, a station selecting device having a rotatable shaft settable to an initial position and to a plurality of station positions, a cam element having a plurality of lobes thereon secured to said shaft and rotatable therewith, means for setting said shaft and cam element to a' desired station position, a gear train having an escapement mechanism operatively connected thereto for controlling the movement of said rotatable shaft, means for releasably arresting said escapement mechanism as the cam element moves into each station position, a pair of contacts adapted to be closed successively by said lobes as the cam element moves into each of said station positions, an electroresponsive device controlled by said pair of contacts having means for releasing said escapement mechanism in response to the closing of said firing contacts, means for maintaining said escapement mechanism released until said cam element has moved into the next succeeding station position, and meanscontrolled by a certain one of said lobes on said camjelement for arming the mine as the cam element moves into said initial position.

.10, In a device for arming a submarine mine arranged within a body of water in response to a changes in said magnetic field, electro-responsive means controlled by said firing contacts for causing said timing mechanism to be advanced from each station setting to the next succeeding station setting, means controlled by said timing mechanism for rendering said firing contacts ineffective during the movement of said mechanism from each station setting to the next succeeding station setting, said last named means being adapted to restore the effectiveness of said firing contacts to control said electro-responsive means as the timing mechanism moves into each of said succeeding station positions, an explosive charge disposed within the mine, means for detonating said explosive charge, and means effective when said mechanism has moved through a predetermined number of station positions for arming the mine whereby said detonating means is adapted to fire said explosive charge in response to the next succeeding operation of said firing contacts.

11. In a system of the character disclosed for controlling the firing of a submarine mine selectively in accordance with a predetermined number of changes in the magnetic field adjacent thereto, a pair of firing contacts adapted to be closed in response to a change in said magnetic field, a station selecting device having an initial position and a plurality of station settings, means including a spring for actuating the station selecting device, means for setting said selecting device to a predetermined station setting, a pair of electrical contacts adapted to be closed as the station selecting device moves into each of said station settings, a slow acting relay operatively connected to said electrical contacts and adapted to be operated by said firing contacts when the electrical contacts are closed, electro-responsive means controlled by said slow acting relay adapted to cause said selecting device to be moved from each station setting by said spring actuating means, means including a control cam element adapted to transfer the control of said station selection device from said electro-responsive device to said control cam element thereby to maintain said station selecting device continuously in operation until the device has been moved from a station setting to said next succeeding station setting, means for maintaining said firing contacts in closed position for a predetermined period of time after the firing contacts are closed thereby to cause said selecting device to move from each station setting sufiiciently to cause said control cam element thereof to be effective, and means effective when the control of said station selecting device has been transferred from said electro-responsive device to said cam element for releasing the slow acting relay and said electro-responsive device.

12. In a system for controlling the firing of a submarine mine, a pair of firing contacts adapted to be closed in response to a change in the magnetic field adjacent thereto, a source of electrical power, means controlled by the pressure of the water Within which the mine is immersed for connecting said firing contacts to said source of power within a predetermined period of time after the mine has been launched, a spring driven timing device Settable at will to different settings, means for causing said timing device to be advanced to the next succeeding setting within a predetermined interval of time after said firing contacts are closed, means for rendering said firing contacts inefiective during the movement of said timing device from each of said settings to the next succeeding setting, detonating means, a pair of normally open contacts in electrical connection with said detonating means, means for closing said normally open contacts when the timing device has moved into a predetermined one of said diiierent settings, and means for causing said detonating device to fire the mine in response to the operation of said firing contacts when the timing device has moved into said predetermined one of said settings.

13. In a device adapted to control the firing of a submarine mine in accordance with a predetermined number of changes in the magnetic field adjacent thereto occurring in predetermined time delayed relation, spring driven means adapted to actuate said device, said spring driven means being adapted to be set to an initial setting and to a plurality of different settings, means including a manipulative device for setting said spring driven means selectively to said different settings thereof corresponding respectively to different degrees of energy stored therein, means for detecting a chan e in said magnetic field and having a pair of firing contacts adapted to be closed as a change in the magnetic field is detected, means controlled by said firing contacts for causing the spring driven means to be moved regressively to said different settings in succession, detonating means, and means controlled by the settings of said spring driven means for operatively connecting detonating means to the firing contacts when said spring driven means has moved regressively through said different settings to said initial setting.

14. In a system for controlling the firing of a submarine mine selectively in accordance with a predetermined number of changes in the magnetic field adjacent thereto, an electric circuit, meansresponsive to a change in said magnetic field for closing said electric circuit, a control device comprising a rotatable cam element having a home position and a plurality of moved positions corresponding respectively to diiferent numbers of changes in the magnetic field required to fire the mine, a first pair of contacts adapted to be closed as the rotatable cam element is moved into any of said moved positions, manipulative means for initially setting said cam element to any of said moved positions, means including a spring driven motor for actuating said cam element, means for releasably arresting said rotatable cam element in any of the moved positions thereof, means including an electro-responsive device adapted to be operated by said circuit closing means when said first pair of contacts are closed for causing the cam element to be released and advanced to the neXt succeeding position, detonating means, a source of power, means effective when said rotatable cam element is moved to said home position for causing said detonating means to be operated by said source of power in response to the closure of said electric circuit by said circuit closing means, and means for preventing the movement of said rotatable cam element beyond said home position and for preventing additional movement of the cam beyond a predetermined moved position.

CHESTER M. VAN A'ITA. RICHARD H. 'WHITEHEAD. 

